Error in excerpt length calculation when using “more”

You are calculating the length of the string down to where the “more” comment block appears in the content, but further functions are applied (strip_shortcodes, strip_tag, stripslashes) to that string which may reduce its size, causing the length calculation to be incorrect.

It’s also worth pointing out that this function is flawed in another crucial way: if you don’t remove all HTML tags for excerpts automatically generated from the post content, you may end up in a situation where HTML tags are truncated or incomplete, which can (and has) break a website’s layout. One solution for this would be to strip all tags from automatically generated excerpts, but allow them when using the more block for example. I ended up overriding this entire function.